class GameStats():
	"""跟踪游戏的统计信息"""
	
	def __init__(self, ai_settings):
		"""初始化统计信息"""
		self.ai_settings = ai_settings
		self.reset_stats()
		
	def reset_stats(self):
		"""初始化在游戏运行期间可能变化的统计信息"""
		self.ships_left = self.ai_settings.ship_limit